WBC super bantamweight champion Rey Vargas and top flyweight contender Julio Cesar Martinez tested positive for minute trace amounts of Clenbuterol, per an announcement from the sanctioning body. The WBC ruled both fighters did not deliberately take any illegal drugs and that the positive tests came from eating contaminated meat, common in Mexico.

The trace amounts of the banned substance inside the two boxers were ruled to have been so insignificant that it wouldn’t have been considered performance-enhancing and as a result of consuming tainted meat. Tainted meat in Mexico has been known to contain Clenbuterol.

This isn’t the first time a world champion had tested positive for Clenbuterol. Back in 2018, Canelo Alvarez tested positive for the banned substance on multiple tests, starting with one in February. Like in the cases of Vargas and Martinez, Alvarez’s team alleged that the positive test came as a result of Alvarez inadvertently consuming tainted meat in Mexico.

Alvarez had been temporarily suspended by the Nevada State Athletic Commission until a hearing on April and could have faced a one-year suspension for the positive tests. The suspension was reduced to six months as Alvarez and Golden Boy Promotions, the company who promotes Alvarez, cooperated with the commission throughout the investigation. The suspension handed to Alvarez was retroactive to the date of the first test.